121 research outputs found

    Saline water and nitrogen doses in the cultivation of West Indian cherry in the post-grafting phase

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    This study aimed to evaluate the photosynthetic pigments and growth of the West Indian cherry cv. BRS 366 Jaburu in the post-grafting phase as a function of the salinity levels of the irrigation water and nitrogen fertilization under greenhouse conditions, in the municipality of Campina Grande-PB. The study was performed in randomized blocks, consisting of two levels of electrical conductivity of irrigation water - ECw (0.8 and 4.5 dS m-1) and four nitrogen doses (70, 85, 100, and 115% of the recommended dose for the crop), with three replications. The synthesis of chlorophyll a and carotenoids in the West Indian cherry plants was inhibited with ECw of 4.5 dS m-1. Nitrogen fertilization in the estimated doses of 92 and 80% of N reduced the effects of salt stress on the contents of chlorophyll a and b in West Indian cherry plants, at 630 days after transplanting. The increment in nitrogen fertilization increases quadratically the absolute and relative growth rate of the diameter in the rootstock of the West Indian cherry plants under irrigation with saline waters.This study aimed to evaluate the photosynthetic pigments and growth of the West Indian cherry cv. BRS 366 Jaburu in the post-grafting phase as a function of the salinity levels of the irrigation water and nitrogen fertilization under greenhouse conditions, in the municipality of Campina Grande-PB. The study was performed in randomized blocks, consisting of two levels of electrical conductivity of irrigation water - ECw (0.8 and 4.5 dS m-1) and four nitrogen doses (70, 85, 100, and 115% of the recommended dose for the crop), with three replications. The synthesis of chlorophyll a and carotenoids in the West Indian cherry plants was inhibited with ECw of 4.5 dS m-1. Nitrogen fertilization in the estimated doses of 92 and 80% of N reduced the effects of salt stress on the contents of chlorophyll a and b in West Indian cherry plants, at 630 days after transplanting. The increment in nitrogen fertilization increases quadratically the absolute and relative growth rate of the diameter in the rootstock of the West Indian cherry plants under irrigation with saline waters

    Application strategies of saline water and nitrogen doses in mini watermelon cultivation

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    Salt stress is highlighted as one of the limiting factors for the establishment of agriculture in the semiarid region of Northeastern Brazil. In this context, it is essential to look for new strategies aiming at minimizing the effects of salt stress on the crops. The present work aimed to evaluate the photochemical efficiency, photosynthetic pigments, and growth of the watermelon cv. Sugar Baby under different use strategies with saline waters and nitrogen fertilization. The experiment was conducted in a protected environment at the Center of Technology and Natural Resources of the Federal University of Campina Grande, municipality of Campina Grande, Paraíba. An experimental design in randomized blocks was adopted, arranged in a 6 x 2 factorial scheme, with six management strategies of water salinity and two nitrogen doses (corresponding to 50 and 100% of the recommendation), with five replications. Two salinity levels of the irrigation water were studied, one with low and another with a high level of electrical conductivity of the water (ECw = 0.8 and 3.2 dS m-1). The watermelon cv. Sugar Baby expressed higher sensitivity to salt stress in the flowering phase, with a decrease in the synthesis of chlorophyll b, chlorophyll total, and carotenoids. The 50% dose of N provided an increment in the initial fluorescence, stem diameter, and the number of leaves of the watermelon cv. Sugar Baby. The length of the main branch of the watermelon plants decreased with the salt stress applied in the fructification phase; however, the fertilization with 100% of N stimulated a higher growth when the irrigation with saline waters was performed at the vegetative and flowering phases.Salt stress is highlighted as one of the limiting factors for the establishment of agriculture in the semiarid region of Northeastern Brazil. In this context, it is essential to look for new strategies aiming at minimizing the effects of salt stress on the crops. The present work aimed to evaluate the photochemical efficiency, photosynthetic pigments, and growth of the watermelon cv. Sugar Baby under different use strategies with saline waters and nitrogen fertilization. The experiment was conducted in a protected environment at the Center of Technology and Natural Resources of the Federal University of Campina Grande, municipality of Campina Grande, Paraíba. An experimental design in randomized blocks was adopted, arranged in a 6 x 2 factorial scheme, with six management strategies of water salinity and two nitrogen doses (corresponding to 50 and 100% of the recommendation), with five replications. Two salinity levels of the irrigation water were studied, one with low and another with a high level of electrical conductivity of the water (ECw = 0.8 and 3.2 dS m-1). The watermelon cv. Sugar Baby expressed higher sensitivity to salt stress in the flowering phase, with a decrease in the synthesis of chlorophyll b, chlorophyll total, and carotenoids. The 50% dose of N provided an increment in the initial fluorescence, stem diameter, and the number of leaves of the watermelon cv. Sugar Baby. The length of the main branch of the watermelon plants decreased with the salt stress applied in the fructification phase; however, the fertilization with 100% of N stimulated a higher growth when the irrigation with saline waters was performed at the vegetative and flowering phases

    Investigação sobre a satisfação do usuário dos serviços prestados pelo Metrô de São Paulo: um estudo exploratório, descritivo e ilustrativo com a utilização do modelo de equações estruturais

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    The applicability in Brazil of the American Customer Satisfaction Index Model using the Structural Equation Modeling technique was discussed. An empirical survey was made of model behavior with data from those using the "Companhia do Metropolitano de São Paulo" - Metro. Results confirmed, in part, the associations of the Model suggesting however that the concept of customer expectations and the relation to other latent variables of the Model must be revised for better results. The impact of this concept on other latent Model variables differed the most from that proposed by Fornell because no sufficiently relevant structural coefficient was obtained. Generally these results corroborated other empirical experiments with such a model showing that consumer satisfaction was much more oriented towards quality and value than to expectations. An overall score of consumer satisfaction was calculated which may be compared to scores obtained with users of similar services.O objetivo desta pesquisa foi discutir a aplicabilidade da metodologia do American Customer Satisfaction Index (ACSI) a situações da realidade brasileira, com base no modelo de equações estruturais. Para tanto, foi realizada uma verificação empírica do comportamento do modelo, aplicando-o à amostra de dados colhida entre usuários dos serviços prestados pela Companhia do Metropolitano de São Paulo - Metrô. Os resultados confirmaram apenas em parte as relações do modelo, sugerindo, principalmente, que para aumentar sua aplicabilidade a situações similares a esta que foi estudada é imprescindível que o conceito de Expectativa e sua relação com as demais variáveis latentes do modelo sejam revistos. O impacto da expectativa nas demais variáveis latentes do modelo é o ponto mais destoante daquele proposto por Fornell, já que nenhum coeficiente estrutural suficientemente relevante foi obtido. Esses resultados, de forma geral, corroboram outras experimentações empíricas envolvendo tal modelo que demonstraram que a Satisfação do Consumidor está muito mais orientada para a Qualidade e para o Valor do que para a Expectativa. A pesquisa ainda calculou um escore global de satisfação do consumidor, que poderá ser comparado a outros escores obtidos entre usuários de serviços afins

    Alocação de fitomassa pela mamoneira sob estresse salino e doses de nitrogênio

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    A escassez de água de boa qualidade é um fator limitante para a agricultura irrigada, principalmente nas regiões áridas e semiáridas e em consequência, a utilização de águas salinas na irrigação das culturas surge como alternativa. Neste sentido, objetivou-se com esta pesquisa, avaliar os efeitos da irrigação com águas salinas e da aplicação de distintas doses de nitrogênio sobre o acúmulo de biomassa da mamoneira cv. BRS Energia, em experimento conduzido em lisímetros sob condições de campo no CCTA/UFCG. Adotou-se o delineamento em blocos inteiramente casualizados em esquema fatorial 5 x 4, testando 5 níveis de salinidade da água de irrigação - CEa (0,3; 1,2; 2,1; 3,0 e 3,9 dS m-1) e 4 doses de adubação nitrogenada (70, 100, 130 e 160% da dose indicada para ensaio em lisímetro) com três repetições. A irrigação com água de CEa até 3,9 dS m-1 não exercem influência negativa sobre a alocação de fitomassa foliar e a razão de fitomassa radicular; A mamoneira cv BRS Energia altera sua alocação de fitomassa em função dos níveis salinos da água, apresentando diminuição na AFC e AFR; A razão de fitomassa caulinar e radicular decresce em função da aplicação de níveis de CEa; Não houve interação entre os fatores níveis de salinidades da água versus doses de adubação nitrogenada sobre as variáveis da mamoneira cv. BRS Energia avaliadas

    COMPOSTAGEM DE RESÍDUOS SÓLIDOS

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    Resíduos são os resultados de processos de diversas atividades da comunidade, sendo de origem industrial, doméstica, hospitalar, comercial, agrícola, de serviços e ainda da varrição pública. Os resíduos apresentam-se nos estados sólido, gasoso e líquido. Produzidos em todos os estágios das atividades humanas, os resíduos, em termos tanto de composição como de volume, variam em função das práticas de consumo e dos métodos de produção. Para solucionar a problemática que envolve os resíduos sólidos, como deposição inadequada em lixões que contaminam o solo e os recursos hídricos e saturação de aterros sanitários, é necessário adotar o gerenciamento integrado de resíduos sólidos que compreendem a redução da geração destes, a reutilização, a reciclagem de materiais que podem servir de matéria prima e a compostagem que trata o resíduo orgânico, dando a este uma nova utilidade. Tendo em vista a problemática da disposição de resíduos sólidos nos mais diversos procedimentos industrias, agroindustrias e domésticos, da sua deposição no ambiente sem tratamento prévio poluindo solos e mananciais hídricos, da possível transmissão de doenças e da busca de alternativas de tratamento desses resíduos, objetiva-se com esse trabalho além da preservação ambiental, a avaliação e estudo do processo de compostagem como método de tratamento de resíduos sólidos

    IMPACTS OF LAND COVER AND GREENHOUSE GAS (GHG) CONCENTRATION CHANGES ON THE HYDROLOGICAL CYCLE IN AMAZON BASIN: A REGIONAL CLIMATE MODEL STUDY

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    O modelo regional BRAMS (Brazilian Regional Atmospheric Modeling System) acoplado ao esquema de vegetação dinâmica General Energy and Mass Transport Model (GEMTM) e cenários de usos da terra na Amazônia e de aumento na concentração dos gases do efeito estufa na atmosfera produzidos a partir das simulações climáticas do Modelo de Circulação Geral Community Climate System Model (CCSM3), do National Center for Atmospheric Research (NCAR), são utilizados para avaliar os impactos no ciclo hidrológico da bacia amazônica. A projeção de desflorestamento para o ano de 2050 e cenário de emissão dos gases do efeito estufa (A2) afetam de forma significativa os balanços de energia e de água, a estrutura dinâmica da atmosfera e, consequentemente, a convergência de umidade e massa na bacia. As mudanças são mais intensas na simulação que existe o efeito combinando do desflorestamento e aumento dos gases do efeito estufa. No cenário de desflorestamento, o mecanismo de retroalimentação positivo é estabelecido, no qual as alterações na circulação regional reduziram a convergência de umidade e a precipitação na região. Nos cenários de aumento dos gases do efeito estufa, sem e com desflorestamento, o mecanismo de retroalimentação é negativo (positivo) na estação úmida (seca), no qual as mudanças na circulação regional também conduziram a redução na precipitação. Os resultados indicam que a rápida destruição da floresta e as mudanças no clima regional decorrente de ações antropogênicas podem tornar-se um processo irreversível, e que as mudanças no ciclo hidrológico e as perturbações na complexa relação solo-planta-atmosfera podem desencadear alterações significativas nos ecossistemas naturais da Amazônia, já que os mesmos não apresentam grande capacidade de adaptação à magnitude das mudanças no clima

    Acute sodium fluorosilicate poisoning in cattle

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    Background: Fluorine is a ubiquitous environmental element and fluoride poisoning in cattle is usually related to the ingestion of contaminated pastures or water, especially near industries, or mineral supplements with excessive amounts of this element. Cattle poisoning can be acute or chronic and is directly associated with the ingested dose and with the duration of exposure. The objective of this study is to report the epidemiological, clinical and anatomopathological aspects of an outbreak of acute sodium fluorosilicate intoxication in cattle. Case: Six 1-year-old, castrated male, mixed breed beef calves from a lot of 60 were found dead without previous clinical signs being observed. The calves died after ingesting a white, odorless, finely granular substance found by the owner near a road that intersected the property. The product was in an open package and identified as sodium fluorosilicate. Of the six dead calves, three were necropsied. Gross lesions were restricted to the digestive system and included varying degrees of hyperemia, hemorrhage, edema, and erosions in the pre-stomach and abomasum mucosae. The histological lesions observed in the three calves were characterized mainly by variable degenerative, necrotic and ulcerative changes in the epithelial lining of the forestomachs and abomasum. Partially (erosion) or totally (ulceration) bare lamina propria of forestomach papillae was covered by cellular debris and neutrophils. Multifocal lymphoid necrosis was seen in lymph nodes and spleen. Fluoride levels measured in the ruminal content of two necropsied calves were 55.2 and 9.17 mgF/kg of dry matter. After the diagnosis and discontinued exposure of the calves to the fluoride product, deaths ceased Discussion: The diagnosis of acute sodium fluorosilicate intoxication in cattle in this study was based on epidemiological, clinical, and anatomopathological findings, and in the determination of fluoride levels in ruminal content. The association of these data constitutes an important aid in suspecting and confirming the diagnosis of intoxication. The acute toxicity of fluoride, observed in the cattle of this study, is relatively rare. The intake of sodium fluorosilicate by cattle may have been favored by the absence of organoleptic properties of the product. The involvement of young cattle revealed an important epidemiological aspect of the condition, since cattle in this age group are the most predisposed to the intoxication due to their greater absorption capacity. The spontaneous ingestion of large amounts of sodium fluorosilicate by cattle of this study produced digestive morphological changes, characterized by variable hyperemia, hemorrhage, and necrosis in the forestomachs and abomasum. The proposed mechanism of lesions is associated with the acidic activity exerted by fluoride on the mucosa. Acute toxicosis must be differentiated from other conditions that cause acute digestive changes in ruminants such as Baccharis spp. poisoning, ruminal acidosis, arsenic poisoning and Baccharidastrum triplinervium intoxication. In these cases, the epidemiological and anatomopathological evidences are extremely important in the differentiation of each condition. Therefore, cattle practitioners should consider acute fluoride poisoning as a differential diagnosis in cattle presenting digestive signs or death without previous signs. Epidemiological, clinical, anatomopathological and the assessment of fluoride levels are important for the accurate diagnosis of this toxicosis

    Acute Sodium Fluorosilicate Poisoning in Cattle

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    Background: Fluorine is a ubiquitous environmental element and fluoride poisoning in cattle is usually related to the ingestion of contaminated pastures or water, especially near industries, or mineral supplements with excessive amounts of this element. Cattle poisoning can be acute or chronic and is directly associated with the ingested dose and with the duration of exposure. The objective of this study is to report the epidemiological, clinical and anatomopathological aspects of anoutbreak of acute sodium fluorosilicate intoxication in cattle.Case: Six 1-year-old, castrated male, mixed breed beef calves from a lot of 60 were found dead without previous clinical signs being observed. The calves died after ingesting a white, odorless, finely granular substance found by the owner near a road that intersected the property. The product was in an open package and identified as sodium fluorosilicate. Of the sixdead calves, three were necropsied. Gross lesions were restricted to the digestive system and included varying degrees of hyperemia, hemorrhage, edema, and erosions in the pre-stomach and abomasum mucosae. The histological lesions observed in the three calves were characterized mainly by variable degenerative, necrotic and ulcerative changes in the epitheliallining of the forestomachs and abomasum. Partially (erosion) or totally (ulceration) bare lamina propria of forestomach papillae was covered by cellular debris and neutrophils. Multifocal lymphoid necrosis was seen in lymph nodes and spleen. Fluoride levels measured in the ruminal content of two necropsied calves were 55.2 and 9.17 mgF/kg of dry matter. Afterthe diagnosis and discontinued exposure of the calves to the fluoride product, deaths ceased.Discussion: The diagnosis of acute sodium fluorosilicate intoxication in cattle in this study was based on epidemiological, clinical, and anatomopathological findings, and in the determination of fluoride levels in ruminal content. The association of these data constitutes an important aid in suspecting and confirming the diagnosis of intoxication. The acute toxicity of fluoride, observed in the cattle of this study, is relatively rare. The intake of sodium fluorosilicate by cattle may have been favored by the absence of organoleptic properties of the product. The involvement of young cattle revealed an important epidemiological aspect of the condition, since cattle in this age group are the most predisposed to the intoxication due to their greater absorption capacity. The spontaneous ingestion of large amounts of sodium fluorosilicate by cattle of this study produced digestive morphological changes, characterized by variable hyperemia, hemorrhage, and necrosis in the forestomachs and abomasum. The proposed mechanism of lesions is associated with the acidic activity exerted by fluoride on the mucosa. Acute toxicosis must be differentiated from other conditions that cause acute digestive changes in ruminantssuch as Baccharis spp. poisoning, ruminal acidosis, arsenic poisoning and Baccharidastrum triplinervium intoxication. In these cases, the epidemiological and anatomopathological evidences are extremely important in the differentiation of each condition. Therefore, cattle practitioners should consider acute fluoride poisoning as a differential diagnosis in cattle presenting digestive signs or death without previous signs. Epidemiological, clinical, anatomopathological and the assessmentof fluoride levels are important for the accurate diagnosis of this toxicosis.Keywords: pathology, toxicology, diseases of cattle, digestive lesions, fluoride
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